1. Field of the Invention
The invention relates to a watertight connector.
2. Related Art
Japanese Unexamined Patent Publication No. 2006-127992 discloses a watertight connector with a housing for accommodating terminal fittings, a one-piece rubber plug arranged on a rear end part of the housing and seal holes through which wires connected to the terminal fittings are to be inserted in a liquid-tight manner. A rubber plug holder is arranged behind the one-piece rubber plug for sandwiching the one-piece rubber plug between the housing and the rubber plug holder by being locked to the housing, and a receptacle-like cap is fit externally to the housing from the front. A busbar body is mounted into a front end part of the housing and is formed by integrating a busbar with a holding body. The terminal fittings are connected to the busbar and short-circuited in a predetermined pattern when the busbar body is mounted into the housing. The cap is fit to the housing after the busbar body is mounted and an opening end part of the cap is held in close contact with a lip formed on the outer periphery of the one-piece rubber plug to prevent intrusion of water into the cap through a clearance between the inner periphery of the cap and the outer periphery of the one-piece rubber plug. The cap has a wide flat opening shape defined by arcuate short side walls that face each other in a lateral direction and straight long side walls facing each other in the vertical direction.
In the process of mounting the cap on the housing, the opening end part of the cap moves onto lips of the one-piece rubber plug and slides. Thus, the lips may be dragged by the cap to tilt. If the last lip largely tilts, this lip may be caught between the rubber plug holder and the cap and it may not be possible to ensure sealing. More particularly, if wires having a large outer diameter are inserted into the seal holes and the one-piece rubber plug bulges out, a large resilient reaction force is applied to the opening end part of the cap from the lip side of the one-piece rubber plug. Although the long side walls can suppress a contact pressure with the lip side by being deflected and deformed, the short side walls are difficult to deflect and deform and, hence, it is difficult to make a contact pressure with the lip side smaller. Thus, the lips tilt more on the short side walls than on the long side walls and the one-piece rubber plug is caught easily.
The invention was completed based on the above situation and aims to provide a watertight connector capable of ensuring sealability by avoiding the catching of a one-piece rubber plug.